Mesoamerican Copper - An Industry of Connections

We are most grateful for this pioneering article on the spread of copper technology in ancient Mexico to Monette Bebow-Reinhard, who is compiling the largest database of copper artifacts ever found, and is developing two books on the topic of copper tooling and trade networks. This article has grown partly out of her vast research library, and from a search for the newest information available. She is editor of the Archaic Copper Newsletter, the only available research publication on the current study of copper, free to anyone interested in seeing this research progress.

Pic 1: Copper Tooling Timeline (Click on image to enlarge)

Mexico was a latecomer to the copper industry. The Old World dates are very general and simply for edification. Annealing, or cold hammering with heat, began in the Great Lakes cultures well before South America. All locations here moved into smelting except where they worked Great Lakes copper. The difference could be that these other locations had pottery and agriculture before their copper industry began, and the Great Lakes Cultures did not. We have some rather widespread dates for these technologies; for instance, an early dating at La Pena puts copper smelting as early as 200 BCE with the cire perdue or lost wax technique similar to that used in lower Central America, Ecuador/Peru and Colombia. While that’s within the range of possibility to learn this from South America, that’s not necessarily what happened; it is, however, the most accepted understanding of Mexican smelting.

Pic 2: Copper needles from different parts of the Americas (Click on image to enlarge)

The cire perdue, or lost wax technique, is described as follows: “An object is molded in wax, encased in clay and fired; the clay becomes pottery and the heated wax melts, runs out, and is replaced with molten metal. When the metal cools, the pottery is broken away and the metal object removed.” Bronze liquid flows easily into thin-walled mold cavities, and the desired colors were silver and gold associated with lunar and solar deities; silver was high arsenic bronze and gold was high tin bronze.

This photo of needles (pic 2) shows similarities between the three copper areas of North and South America. There are opponents to diffusion, saying that these could be independent innovations. Sure, they could. But if we can accept trade, why not the sharing of ideas?

Pic 3: Boat Route to West Mexico (Click on image to enlarge)

This boat route demonstrates how South America could have had contact with West Mexico. This is considered most likely rather than coming up by land because these types of tools are completely absent from southern Mexico through Nicaragua between 200 and 600 CE. Valentini wrote about copper in the late 1800s, and confessed he had never seen a bronze Mexican artifact; he only assumed they existed because of the writings of Cortez and others. But he indicated that in Nicaragua they found traces of smelting furnaces and another at the Barnard site west of Acapulco in West Mexico—traces that are likely gone today, because they were not mentioned in any modern sources found. So we cannot completely discard the contact overland route.

Pic 4: West Mexico (Click on image to enlarge)

Mexico’s largest copper source encompasses the modern states of Guerrero, Michoacan and Jalisco, Colima and Nayarit in the shaded part of this map (pic 4). People living in this copper rich area had complex village settlements by 600 CE; it would seem these settlements with extensive public and ceremonial architecture date to the beginnings of the copper tooling industry. They were also agriculturalists and potters.

Pic 5: Copper findings at Amapa (Click on image to enlarge)

Artifacts found at Amapa (see pic 5) were beaten and cold cast, with similarities noted to Ecuador and Peru, but there are also similarities to Great Lakes tools. At Amapa metal-working became an active industry by 900 CE and lasted about 300 years. 205 copper artifacts were uncovered in excavation in 1959. In this same region they found annealed native copper as early as 500 CE in some tombs, and these artifacts were believed to have originated here.

At an excavation of Teotihuacan (the orange star, pic 6), a small low-arsenic, copper-arsenic figurine was found that indicates West Mexico was smelting as early as 700 CE. Hosler noted that the timing of metallurgy coincided with the collapse of Teotihucan and “with the formation of smaller polities in many Mesoamerican areas. These events reconfigured loyalties, alliances, and trade networks, and may have provided a particularly propitious moment for the introduction of a new and exotic material,” she noted.But as we’ve seen so far, it may not have been an introduction at all. Could Teotihuacan have collapsed in part because they could not control this new technology?

Pic 7: A father teaches his son to cast gold, Codex Mendoza, folio 70 (Click on image to enlarge)

A pictograph in the Codex Mendoza (pic 7) demonstrates that the Aztecs used a flute-like pipe to blow the fire hot for casting. Bernal Diaz, however, said this was not similar to methods used by the Spanish. Valentini noted, “If the Mexican goldsmith, with the aid of a blowpipe, was able to increase the heat of the fire to such a degree as to make gold fusible, a heat which requires 1,100 degrees Celsius, he cannot have found greater difficulties in melting copper, which requires nearly the same degree of heat; and tin, which is far more easily fusible, could have been treated in the same way.”

Pic 8: Tinklers found at Casas Grandes (Click on image to enlarge)

There was a clear connection found with copper artifacts at Casas Grandes (Paquime) in northern Mexico—including over 21,000 tinklers (pic 8), at least one dated to 975 CE, and Casas Grandes had some connection to the Toltecs. Casas Grandes may have been a mercantile center, a location built and controlled by Chacoamericans (time sensitive name for Southwest U.S. cultures) to access trade from southern and central Mexico; acting as a connection site between the Mesoamericans and the distinct groups such as Hohokam and Anasazi. But while there’s been a potential workshop found, no smelting site has been noted. After 1300 CE, Casas Grandes became known as a rich source of raw copper.

Pic 9:Various Artifacts and their Locations (Click on image to enlarge)

Bells were the largest percentage of goods created from copper and bronze, cast to fall within a range of pitches. Sounds were essential in rain-making ceremonies, reproducing the sounds of thunder, rain and the roar of the jaguar. Metal came to be synonymous in several local languages for bell. In contrast, bells were only of minor significance in South America, and tinklers or beads rather than bells were used by Great Lakes Cultures. Color is another reason given for the switch to casting with alloys.The crescent is a shape commonly found for many diverse purposes in the Great Lakes Cultures. As a Mesoamerican tool they have been referred to, not as crescents, but variably as knives, implements, axes, and also as axe-monies.Copper casting could have been done in the Honduras, where a copper ingot was found, and they are a source for copper. These copper bells (pic 9) are particularly distinctive. Bronze tools were produced in relatively small numbers compared to ritual and status objects—bronze enhanced the tonal sounds of bells. This turtle shell (pic 9) and other artifacts here could be bronze but were not labeled as such.A site associated with the Tarascans was Itziparatzico in Western Mexico. Archaeologists have identified a Late Postclassic regional center of copper production here. The scale of production indicates that part-time specialists cast copper to supply the Tarascan state, which was predominantly agricultural. The Tarascans of Michoacan were considered to be next in power to Aztecs from 1350 to conquest. These figurines of copper (pic 9) are part of what they created.

Helen Pollard stated at the recent Mesoamerican Conference in Chicago that Dorothy Hosler’s bronze research is most likely wrong, because the bronze artifacts found were only such that could have been created ‘by accident.’ Caley and Easby discovered bronze mixed with tin from a source in West Mexico where it was excavated, and that makes the alloy process here sound pretty deliberate. Another source noted that all points and arrowheads in Aztec territory were made of bronze, which they created by mixing 10% tin with 90% copper to harden it enough to chop wood.Determining their attitude and desire is difficult from a study of percentage of tin. As Hosler noted, they were likely experimenting with different blends of alloys to try to come up with different sounds for bells. This is certainly better than attributing their bronze to sheer accidental mixture. That they were at the beginning of a Bronze Age cannot be denied. I might also suggest that many bronze tools and bells discovered could have been misidentified as copper.

Pic 11: Smelting furnace (Click on image to enlarge)

Smelting practices, like annealing, needed close proximity to water and all slag (see pic 12) was found close to three freshwater springs. They found no trace of any smelting furnace with slag at Itziparatzico; however, there can be no other accounting for the slag, which is smelting byproduct. Forged and hammered copper objects were also found in the area. Shown here is a potential smelting furnace from El Manchon.

Pic 12: Potential copper sites (Click on image to enlarge)

Here (pic 12) we see all the sites found in this research, both where slag and furnaces were found, and where a lot of copper activity revealed a potential worksite. They also found copper in the Yucatan, in a cenote at Chichen Itza in the Late Post Classic. Over a hundred metal artifacts were recovered at Lamanai, a large Mayan center in Belize; there is a localized copper deposit in the Mayan Mountains in the southern portion of Belize. While the site was occupied since 200 BCE, none of the artifacts tested dated before 1300 CE.

Pic 13: Aztec copper; photos courtesy of the Division of Anthropology, American Museum of Natural History (Click on image to enlarge)

For the Aztecs, copper was something they traded for, but it became very important to them as axe-monies. Three Aztecan related communities used this symbol in a reddish color for their town name glyph. According to the database at the American Museum of Natural History in New York, axe-monies were crescent-shaped and appeared to be cutting tools with handles, as shown here (pic 13). Oddly, however, this other photo of an axe (or celt) shaped copper sheet seems a more likely fit to the town name glyphs. Many of the crescent axe-monies found were from Oaxaca, but most were not called axe money; only a few found in this database had that denotation. The Aztecs also traded in bells, and valued copper carpenter tools, such as the larger axes and probably celts—but celts such as in this photo, as a thin sheet, had no value as a tool. West Mexican copper and bronze show up at their sites at Cuexcomate and Yautepec, where they wanted primarily toolsawls, punches and needles, instead of elite items. If the Tarascans controlled the copper trade, then they had some kind of trade agreement with the Aztecs, along with the ability to remain independent.

Pic 14: The Huastec region (Click on image to enlarge)

In the Huastec region in northern Veracruz they found hammered sheets of copper and bells with a variety of alloy compounds dating back to 900 CE, along with trade material from Cahokia and Spiro. This map (pic 14) shows those locations and the blue star represents Poverty Point, a hunting-gathering village with a mound, which takes the copper industry back to 1800 CE, pre-dating the Olmecs. Don’t these little heads look Olmec-influenced? But no copper artifacts have turned up at any known Olmec site, although a great number of artifacts were found in Oaxaca, which would be south and west of Tula on this map.

Pic 15: Copper connections timeline (Click on image to enlarge)

Here (pic 15) are some timelines where I inserted copper connections. I would not reject an on-going relationship between the U.S. cultures and Mesoamericans at any time following the creation of the copper industry, which by the way is earlier than anything uncovered in Mesoamerica so far. More work needs to be done to understand these smelting areas and transitions. But Hosler’s copper transition from Period 1 to Period 2 appears to be both a movement of people as well as one of casting bronze alloys since they were smelting copper early in the industry. It’s apparent that if the Spanish hadn’t conquered Mexico when they did, this Bronze Age evolution would have continued. As with all peoples, this exploration of an industry indicates that competition in trade breeds innovation.

SOURCES:-Bower, Bruce. “Late Maya Culture gets an Island Lift.” Science News, Vol. 136, Issue 2, July 8, 1989Caley, E.R. & Easby, D.T. Jr. “Indium as an impurity in Western Mexican tin and bronze artifacts,” Science 1967, February 10; 155(3763): 686-7Coe, Michael. Mexico: From the Olmecs to the Aztecs. New York: Thames and Hudson, 1994Di Peso, Charles. Casas Grandes: A fallen trading center of the Gran Chichimeca. Flagstaff, Ariz.:Northland Press, 1974 Pic 8 photo of tinklers is from hereHandbook of the North American Indians: Volume 9: Southwest. Alfonso Ortiz, editor. Washington: Smithsonian Institute, 1979Hosler, Dorothy. “Excavations at the Copper Smelting Site of El Manchon, Guerrero, México.” Foundation for the Advancement of Mesoamerican Studies, Inc. (FAMSI), 2004 Pic 11 is from here----------. “Recent Insights into the Metallurgical Technologies of Ancient Mesoamerica.” Journal of Metals 51 (5): 1999----------. “West Mexican Metallurgy: Revisited and Revised.” Journal of World Prehistory, 2009 Needles on left in Pic 2 from here; on right from author’s artifact collection; maps in Pic 4 from here---------- and A. McFarlane. “Copper Sources, Metal Production and Metals Trade in Late Postclassic Mesoamerica.” Science 273:1996 Pic 3 from hereMaldonado, Blanca. “Tarascan Copper Metallurgy at the site of Itziparatzico, Michoacan, Mexico.” FAMSI, 2005 Pic 12 ore from hereMcAnany, Patricia A. “Exchange in the Maya Lowlands,” The American Southwest and Mesoamerica“New Museum Exhibits Teotihuacan Objects,” Instituto Nacional de Antropologia e Historia http://www.inah.gob.mx/index.php/english-press-releases/50-museums-and-exhibitions/4963-new-museum-exhibits-teotihuacan-style-objects April 6, 2011Pauketat, Timothy. “America’s First Pastime.” Archaeology, September-October 2009, 21. Map in Pic 14 from here. Poverty Point heads from ‘American Antiquity’, Vol. 33, No. 1, 1968Pendergast, David. “Metal Artifacts at Amapa, Nyarit, Mexico.” American Antiquity, Vol. 27, no. 3, 1962, accessed at JStor. Photo in Pic 5 found hereSmith, Michael E. “Yautepec, an Aztec City,”http://www.public.asu.edu/~mesmith9/yaucity.html“Tamtoc,” Tom Gidwitz, http://www.huasteca.tomgidwitz.com/html/tamtoc.htmlValentini, Philipp J.J. PhD. Mexican Copper Tools: the use of copper by the Mexicans before the conquest, and The Katunes of Maya History, a chapter in the early history of Central America, with special reference to the Pio Perez Manuscript, published by BiblioLife, nd; article published by the Press of Charles Hamilton, Mass., 1880 Photos in Pice 7 and Pic 13 found hereWeaver, Muriel Porter. The Aztecs, Maya and Their Predecessors. New York: Seminar Press, 1972.Map in Pic 6 created from one found in Herbert Spinden’s 1928 book, ‘Ancient Civilizations of Mexico and Central America’, published by the American Museum of Natural HistoryPic 10 Bronze photo from an artifact auction site and I do not wish to share the linkPic 13 axe and crescent photo Courtesy of the Division of Anthropology, American Museum of Natural History. 30/134 is Axe-Monies (crescent) and 30.2/9380 F is axe (celt) shaped copper sheetIncludes personal conversations with Elizabeth Paris (January 2013), author of “Metallurgy, Mayapan and the Postclassic World System,” Ancient Mesoamerica 19 (1):43-66• Acknowledgements: Adam Reinhard for help with graphics. Beau Anderson supplied the link to the Maldonado article. Special thanks to Mike Ruggeri, who runs the Aztlan e-list and has given me access to other experts in the field: Tim King, Jerry Offner, Rick McCallister, Nick Hopkins, Dea Urquidi, Joe Mountjoy and Jeff Baker.

4 At 2.26pm on Monday April 21 2014, Saurabh Chandra wrote:

3 At 6.55pm on Tuesday April 9 2013, Monette Bebow-Reinhard wrote:

Amazing, Nat - and here I thought I was using smelt the way everyone else was! Thanks for this!

Mexicolore replies: (Editor’s note:) we’ve now made some corrections to the text to reflect these points.

2 At 3.25pm on Tuesday April 9 2013, nat wrote:

Great Article, though I think you are misusing the word “smelt”. “Smelting” is to extract the metal from the ore. “Casting” is to make it into something (using the lost wax process for instance). One must smelt the ore to make it a useable metal. At this time it is often alloyed with other metals to obtain more useful characteristics. Bronze being an alloy of copper that is much harder.